docs: def get_cpu_props(cls, family, arch='x86'):
          """
          Get CPU info XML
  
          Args:
              family(str): CPU family
              arch(str): CPU arch
  
          Returns:
              lxml.etree.Element: CPU xml
  
          Raises:
              :exc:`~LagoException`: If no such CPU family exists
          """
  
          cpus = cls.get_cpus_by_arch(arch)
          try:
              return cpus.xpath('model[@name="{0}"]'.format(family))[0]
          except IndexError:
              raise LagoException('No such CPU family: {0}'.format(family))